Do Testosterone Booster Supplements Work? Here's What Science Has to Say

by Elliot Reimers, M.S.(C), CISSN, CNC | Reviewed by Advisory Board

Do Testosterone Booster Supplements Work? Here's What Science Has to Say

Testosterone Boosters that Work (According to Science)

It's only human nature that so many men buy into the hype behind testosterone-booster supplements. After all, testosterone is quite literally what makes a man a man. Yet, bodybuilders and gym-goers alike waste thousands of dollars on bunk supplements that claim to “increase sex drive" and "ramp up test levels by 500% in just one week!”

Claims like that should be a major red flag when you're shopping for natural testosterone boosters or any other dietary supplements. Just think, if a supplement contained ingredients so potent that it increased your testosterone levels four-fold in one week, it wouldn’t be sold at the local supplement shop. 

As the adage goes: If it’s too good to be true, it usually is.

However, not all supplements are bogus. Quite the opposite, actually. A quality testosterone booster may be well worth the investment if your goal is to build muscle mass, improve body composition, and enhance overall vitality.

The testosterone-supporting ingredients covered in this article have compelling human studies to back their efficacy. Curious to learn more? Read on and we'll get you up to speed.

Why Boost Testosterone Levels?

Testosterone is the primary anabolic androgenic steroid (AAS) produced in males. Steroids are cholesterol-derived hormones that fall into one of five categories: androgens, estrogens, progestins, mineralocorticoids, and glucocorticoids. In humans, all steroids are synthesized through a series of enzymatic modifications of cholesterol via steroidogenesis (see diagram below).

Testosterone is particularly important in humans due to its myriad roles as a mediator of anabolic reactions. Anabolic reactions use energy to create new complex molecules, such as muscle protein; catabolic reactions do the inverse (i.e. break down complex molecules to release energy). Hence, testosterone is well-known to encourage muscle growth [1].

In addition to its anabolic properties, testosterone is the central hormone regulating the development and maturation of masculine characteristics, such as facial hair growth and deepening of the voice.

Increasing Testosterone Through Mother Nature and Science

There are a select few supplement ingredients that can boost testosterone levels naturally. Ironically, they often don't find their way into supplements that claim to increase testosterone. Here are the five to look for:

1.  Ashwagandha

ashwagandha testosterone

Ashwagandha (Withania somnifera) is a fruit-bearing plant belonging to the nightshade family. It's natively found in the African and Middle East regions of the world and has been used in Ayurveda for centuries to support the immune system [2]. 

Ashwagandha is an exemplar “adaptogenic herb” due to its multifarious therapeutic properties, notably as a stress-reliever and vitality-enhancer [3]. Adaptogens like ashwagandha are herbs that help the body “adapt” to stress and restore homeostasis.

The leaves and roots of ashwagandha contain numerous constituents, such as saponins, alkaloids, and steroidal lactones called withanolides. In fact, the first known withanolide, withaferin-A, was discovered in the roots of ashwagandha. Withanolides are the key bioactive compounds in ashwagandha, with a large body of evidence showing these constituents have anti-inflammatory, anti-hypertensive, antioxidant, anxiolytic, and immune-boosting benefits in humans [3]. 

So, how does this tie into testosterone? Well, several recent clinical studies found that supplementing with 600 mg of ashwagandha extract daily can increase testosterone levels by as much as 40% and enhance fertility in men [4]. The biochemical mechanisms governing ashwagandha's test-boosting actions are quite complex on a molecular level. To put it simply, withanolides like withaferin-A regulate the activity of specific proteins/enzymes in cells so as to maintain homeostasis.  

When shopping for a testosterone-booster supplement, ensure the formula contains KSM-66® Ashwagandha or Sensoril® Ashwagandha. These are gold-standard extracts of organic ashwagandha that guarantee consistent potency and purity.

2.  Tongkat Ali (Longjack)

Tongkat ali (Eurycoma longifolia), aka longjack, is arguably the most compelling natural testosterone booster. This slender shrub is indigenous to Indochina regions and parts of the Philippines. Longjack has been a staple in traditional Chinese medicine due to its purported aphrodisiac and libido-enhancing effects [5].

Root extracts of longjack contain a variety of phytochemicals called quassinoids, notably eurycomanone, that are responsible for enhancing sex drive and stimulating testosterone production [6]. An 8-week pilot study involving active adult males found that those taking 100 mg of a longjack supplement daily had significantly greater improvements in fat-free (lean) mass (FFM), body fat percentage (FM), maximal strength (1RM), and arm circumference compared to those in the placebo group [7]. Further research has shown that Eurycoma longifolia extract favorably alters the ratio of testosterone to cortisol after exhaustive exercise [8].

3.  Diindolylmethane (DIM)

DIM is a metabolite derived from indole-3-carbinol (I3C) found in cruciferous vegetables like broccoli and cauliflower.  Research has found that DIM exhibits both “selective estrogen receptor modulator” (SERM) and “selective androgen receptor modulator” (SARM) activity, suggesting it can help control androgen and estrogen balance in men and women [9, 10]. DIM has also been shown to inhibit prostate cancer cell proliferation in vitro and activate liver enzymes that expedite the clearance of estrogen metabolites from the body [11, 12].

DIM estrogen

Excess estrogen can reduce testosterone levels in men by curtailing androgen receptor activity and reducing the synthesis of gonadotropin-releasing hormone in the hypothalamus. In this regard, supplementing with DIM presents an indirect way of boosting testosterone since men with high estrogen often experience symptoms resembling those of low testosterone.

4.  Boron

Boron is a trace mineral found mainly in avocado, dried fruit (e.g. raisins), and legumes. Research on supplemental forms of boron shows promising results with regards to testosterone levels in men. For example, a study conducted at the University of Medical Sciences in Tehran found that men who supplemented with 10 mg of boron at breakfast for just seven days increased their testosterone levels by upwards of 30% from baseline while subsequently lowering their estradiol (estrogen) levels by nearly 40% [13].

More human data is necessary to confirm how boron boosts testosterone, but the preliminary evidence is promising. Scientists postulate that boron uncouples sex steroids from their transporters, such as sex-hormone-binding globulin (SHBG) [14]. In turn, this can increase the amount of free testosterone in the body.

5. Zinc

Transparent Labs ZMO

Like boron, zinc is a crucial trace mineral involved in a multitude of vital biological functions, especially immunity, reproduction, and hormonal balance.  As such, zinc plays a crucial role in supporting healthy testosterone levels and sperm cell counts in men.

Several studies involving adult male athletes and aging men have shown that supplemental zinc significantly increases bioavailable/free testosterone and promotes fertility [15, 16]. Further evidence suggests that zinc modulates the conversion of androstenedione, an androgen precursor, to testosterone [17]. Zinc also inhibits the metabolism of testosterone to dihydrotestosterone (DHT) by the liver enzyme 5-alpha-reductase, thereby conferring benefits for prostate health [18]. 

Zinc comes in a variety of supplemental forms, the most effective of which include zinc picolinate, zinc citrate, and zinc glycinate. For boosting testosterone and encouraging healthy immune function, aim for 10 to 15 milligrams of elemental zinc per day.

Finding a Testosterone Booster that Works

Whether your goal is to enhance your sex drive, improve your fitness, encourage a healthy immune system, promote hair growth, or build muscle, testosterone plays a vital role. As such, the effects of supplements that increase testosterone levels can be quite pronounced.

But remember to approach grandiose supplement claims with a sense of skepticism, especially when it comes to products promising to increase your testosterone levels. Your first intuition should be the read the supplement facts panel and verify the formula contains ingredients backed by science, like the ones discussed in this article. It's much better to spend a little extra for a quality testosterone booster as opposed to buying cheap snake oil.

Transparent Labs Vitality features evidence-based doses of premium ingredients, including LJ100® longjack, KSM-66® ashwagandha, and PrimaVie® shilajit to help naturally boost testosterone and control estrogen.

Elliot Reimers, M.S.(C), CISSN, CNC
Elliot Reimers, M.S.(C), CISSN, CNC


Elliot holds a B.S. in Biological Sciences from the University of Minnesota, as well as being a Certified Sports Nutritionist (CISSN) and Certified Nutrition Coach (CNC). He is currently pursuing a Master's of Science in Molecular Pharmacology and Toxicology at Michigan State University. Elliot began freelance writing circa 2012 and has since written 100s of articles and several eBooks pertaining to nutritional science, dietary supplements, exercise physiology, and health/wellness. Being a “science whiz,” he has a passion for helping people understand how nutrients (and other chemicals) and exercise work on a cellular and molecular level so they can make smarter choices about what they put in, and do with, their bodies. When Elliot is not busy writing or studying, you can find him pumping iron, hiking the mountains of beautiful Colorado, or perusing nutraceutical research.

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